Is the Child Opportunity Index a Factor in Surgical Outcomes for Adolescent Idiopathic Scoliosis?

BACKGROUND: Low socioeconomic status (SES) has been previously associated with delays in orthopaedic care. However, it is unclear how SES impacts patients with adolescent idiopathic scoliosis (AIS), particularly regarding preoperative major coronal curve angle or surgical outcomes. Utilizing the Child Opportunity Index (COI)-an address-driven measure of pediatric education, health/environment, and SES-we investigated whether COI is associated with differences in preoperative scoliosis magnitude, age at surgery, and AIS surgical outcomes. METHODS: Consecutive patients with AIS surgically treated at a single center from 2011 to 2017 were reviewed. COI was calculated by inserting a patient's home address into the nationally available COI database to derive a COI value. COI is scored from 0.0 to 100.0 (0.0 is lowest, 100.0 is highest). Specifically, COI is categorized as very low (<20.0), low (20 to 39.9), moderate (40 to 59.9), high (60 to 79.9), and very high (≥80). Those without addresses were excluded. Patients without proper radiographs to assess curve correction were also excluded. A COI threshold of 60.0 was used to separate patients into a low (<60.0) or high COI ( ) group based on published COI guidelines. Outcomes, including preoperative curve magnitude, age at surgery, percentage curve correction, operative time (OT), intraoperative estimated blood loss per level fused, length of stay, and complications, were compared across groups. Pearson correlation analysis was used to assess correlations between COI and preoperative curve magnitude, as well as age. RESULTS: Four hundred four patients were included in the study, and 263 had 2-year follow-up data. Patients were an average age of 14.9 years old (range: 11.2 to 19.8), had a median COI of 76 (range: 4 to 100), and had a mean preoperative major curve angle of 59 degrees (range: 36 to 93). COI was significantly higher for white patients compared with non-white (80.0 vs 40.0, P < 0.001), and higher for non-Hispanic individuals (79.0 vs 15.0, P < 0.001). Patients with Low COI were associated with a lower OT per level fused ( P = 0.003) and decreased postoperative complication risk ( P = 0.02). COI was not associated with preoperative major coronal curve angle, age at surgery, or any other surgical outcomes. CONCLUSION: COI was significantly lower for non-white patients and those of Hispanic ethnicity. Patients from low COI backgrounds achieved similar surgical results as those from high COI addresses and had a decreased OT per level fused and complication incidence, though the clinical significance of these differences is unknown. Future prospective studies are needed to determine whether these findings are reproducible across other states and health systems. LEVEL OF EVIDENCE: Level III-prognostic study.

Novel Surface Topographic Assessment of Lung Volume and Pulmonary Function Tests in Idiopathic Scoliosis: A Preliminary Study.

OBJECTIVE: Severe spinal deformity results in restrictive pulmonary disease from thoracic distortions and lung-volume limitations. Though spirometry and body plethysmography are widely accepted tests for pulmonary function tests (PFTs), they are time-consuming and require patient compliance. This study investigates whether surface topographic [surface topography (ST)] measurements of body volume difference (BVD) and torso volume difference between maximum inhale and exhale correlate to values determined on PFTs. METHODS: This study included patients with idiopathic scoliosis and thoracic/thoracolumbar curves ≥40 degrees. Patients received ST scans, clinical examinations, and EOS biplanar radiographs on the same day. PFTs were performed within 3 months of ST/radiographic analysis. Univariate linear regression analysis was used to examine relationships between BVD, PFT values, and mean curves. RESULTS: Sixteen patients (14.6 ± 2.2 y, 69% females) with idiopathic scoliosis and mean thoracic/thoracolumbar curves of 62 degrees ± 15˚ degrees (45 degrees to 93 degrees) were assessed. BVD displayed statistically high-positive positive correlations with forced vital capacity ( R = 0.863, P < 0.0001), forced expiratory volume in 1 second ( R = 0.870, P < 0.001), vital capacity ( R = 0.802, P < 0.0001), and TLC ( R = 0.831, P < 0.0001. Torso volume difference showed similarly high positive correlations to forced vital capacity, forced expiratory volume in 1 second, vital capacity, and TLC, but not residual volume. No correlations emerged between the mean thoracic/thoracolumbar curve and BVD or PFT values. CONCLUSION: This study strongly endorses further investigation into ST scanning as an alternative to traditional PFTs for assessing pulmonary volumes. The noncontact and noninvasive nature of ST scanning presents a valuable alternative method for analyzing thoracic volume, particularly beneficial for patients unable to cooperate with standard PFTs. LEVEL OF EVIDENCE: Level II-prognostic.

Do Adolescent Idiopathic Scoliosis Patients With Vitamin D Deficiency Have Worse Spine Fusion Outcomes?

BACKGROUND: Prior research has shown that patients with adolescent idiopathic scoliosis (AIS) have a higher prevalence of vitamin D deficiency compared with healthy peers. In adult orthopaedic populations, vitamin D deficiency has been shown to be a risk factor for higher reported pain and lower function. We investigated whether there was an association between vitamin D levels and AIS patient-reported outcomes, as measured by the Scoliosis Research Society (SRS-30) questionnaire. METHODS: This was a single-center, cross-sectional study. Postoperative AIS patients were prospectively recruited during routine follow-up visits, 2 to 10 years after spine fusion. Vitamin D levels were measured by serum 25-hydroxyvitamin D (ng/mL). Patients were categorized based on vitamin D level: deficient (<20 ng/mL), insufficient (20 to 29 ng/mL), or sufficient (≥30 ng/mL). The correlation between vitamin D levels and SRS-30 scores was analyzed using multivariable analysis and pair-wise comparisons using Tukey method. RESULTS: Eighty-seven AIS patients (83% female) were enrolled who presented at median 3 years (interquartile range: 2 to 5 y; range: 2 to 10 y) after spine fusion. Age at time of surgery was mean 15 (SD±2) years. Major coronal curves were a mean of 57 (SD±8) degrees preoperatively and 18 (SD±7) degrees postoperatively. It was found that 30 (34%) of patients were vitamin D sufficient, 33 (38%) were insufficient, and 24 (28%) were deficient. Although there was no correlation between vitamin D level and Pain, Mental Health, or Satisfaction domains ( P >0.05), vitamin D-deficient patients were found to be younger ( P <0.001) and had lower SRS-30 function ( P =0.002), Self-image ( P <0.001), and total scores ( P =0.003). CONCLUSIONS: AIS patients with vitamin D deficiency (<20 ng/mL) are more likely to be younger age at time of surgery, and report lower Function, Self-image, and Total SRS-30 scores postoperatively. Further work is needed to determine whether vitamin D supplementation alters curve progression and patient outcomes. LEVEL OF EVIDENCE: Level II-prognostic study.

Quantitative Sensory Changes Following Posterior Spinal Fusion to Treat Adolescent Idiopathic Scoliosis.

BACKGROUND: Sensory changes surrounding the incision frequently develop after posterior spinal fusion (PSF) to treat adolescent idiopathic scoliosis (AIS). Anecdotally, patients may experience sensory changes on the chest wall. Such postsurgical sensory changes are not well described quantitatively. This study aims to evaluate the presence, intensity, and duration of mechanical sensory changes in AIS patients postoperatively. METHODS: A prospective cohort of AIS patients, 10 to 21 years old, was followed. Quantitative sensory testing (QST) included touch detection threshold [mechanical detection threshold (MDT)] and pain detection threshold (MPT), using VonFrey monofilaments and pinprick stimulators. QST was performed at 3 sites at T6: the right and left chest at the nipple line and adjacent to the incision below the inferior angle of the scapula. QST at the thenar eminence was the control. QST was collected at baseline, 3 days, 1, and 6 months postoperative. RESULTS: Thirty-four patients (21% males; mean age: 14.9 years old; median preoperative curve: 58 degrees) completed all testing. Mean deformity correction was 64% (SD: 10.4). Adjacent to the incision site, MDT was significantly higher compared with baseline at 3 days and 1 month ( P < 0.001) but not at 6 months ( P = 0.19), whereas MPT was significantly higher at 3 days, ( P < 0.001), 1 month ( P < 0.001), and 6 months ( P = 0.001). For the chest wall in all patients, MPT was higher on the left chest at 3 days ( P = 0.04) and on the right chest at 3 days ( P = 0.022) and 1 month ( P = 0.05). For patients with right-sided curves, MDT ( P = 0.01) and MPT ( P = 0.015) overall were significantly higher on the concave side (left) chest postoperatively. CONCLUSIONS: PSF is associated with sensory disturbances that are detectable within days, persist at 1 month, and improve at 6 months postoperatively adjacent to the incision and on the chest wall. We suspect that these sensory changes are transient. Describing postoperative sensory changes will help us better set postoperative expectations for patients undergoing PSF. LEVEL OF EVIDENCE: Level I.

Exploring Correlations Between Pain and Deformity in Idiopathic Scoliosis With Validated Self-reported Pain Scores, Radiographic Measurements, and Trunk Surface Topographic Measurements.

BACKGROUND: Up to 75% of patients with idiopathic scoliosis (IS) report back pain, but the exact contributors are unclear. This study seeks to assess how pain correlates with demographics, radiographic and surface topographic (ST) measurements, and patient-reported outcome measures (PROMs) in patients with IS. METHODS: Patient-Reported Outcome Measurement Information System (PROMIS) Pain Interference (PI) and Scoliosis Research Society revised (SRS-22r) pain domain from an IRB approved prospectively collected registry containing patients 11 to 21 years old with IS were correlated (Spearman coefficients) with measurements from whole-body EOS radiography and ST scanning, PROMIS 1.0 PROMs, Trunk Appearance Perception Scale (TAPS), and SRS-22r domains. SRS-22r and PROMIS-PI were also compared between different sex, scoliosis severities, and primary curve locations with Mann-Whitney U or Kruskal-Wallis tests, and if significant differences were found, included with the 5 highest univariate correlated variables into stepwise multivariate linear regression models ( P <0.05 to enter, P >0.1 to remove) predicting SRS-22r pain and PROMIS-PI. RESULTS: One hundred and forty-nine patients (14.5 ± 2.0 y, body mass index 20.6 ± 4.1 kg/m 2 , 96 (64%) female, mean major coronal curve 40 ± 19 deg, range: 10 deg, 83 deg) reported mean PROMIS-PI of 42.2 ± 10.0 and SRS-22r pain of 4.4 ± 0.6. SRS-22r self-image was the most correlated variable with both SRS-22r pain (rho=0.519) and PROMIS-PI (rho=-0.594). Five variables, none of which were ST or radiographic measures, strongly predicted SRS pain domain (R=0.711, R2=0.505, N=138). Two variables (SRS-22r self-image and SRS-22r function) were utilized by a model correlated with PROMIS-PI (R=0.687, R2=0.463, N=124). CONCLUSIONS: SRS-22r function and self-image domains were more strongly correlated with SRS-22r pain and PROMIS-PI than any radiographic or ST measurements. LEVEL OF EVIDENCE: Level II-retrospective study.

The classification of scoliosis braces developed by SOSORT with SRS, ISPO, and POSNA and approved by ESPRM.

PURPOSE: Studies have shown that bracing is an effective treatment for patients with idiopathic scoliosis. According to the current classification, almost all braces fall in the thoracolumbosacral orthosis (TLSO) category. Consequently, the generalization of scientific results is either impossible or misleading. This study aims to produce a classification of the brace types. METHODS: Four scientific societies (SOSORT, SRS, ISPO, and POSNA) invited all their members to be part of the study. Six level 1 experts developed the initial classifications. At a consensus meeting with 26 other experts and societies' officials, thematic analysis and general discussion allowed to define the classification (minimum 80% agreement). The classification was applied to the braces published in the literature and officially approved by the 4 scientific societies and by ESPRM. RESULTS: The classification is based on the following classificatory items: anatomy (CTLSO, TLSO, LSO), rigidity (very rigid, rigid, elastic), primary corrective plane (frontal, sagittal, transverse, frontal & sagittal, frontal & transverse, sagittal & transverse, three-dimensional), construction-valves (monocot, bivalve, multisegmented), construction-closure (dorsal, lateral, ventral), and primary action (bending, detorsion, elongation, movement, push-up, three points). The experts developed a definition for each item and were able to classify the 15 published braces into nine groups. CONCLUSION: The classification is based on the best current expertise (the lowest level of evidence). Experts recognize that this is the first edition and will change with future understanding and research. The broad application of this classification could have value for brace research, education, clinical practice, and growth in this field.

Sprengel's deformity: an analysis of surgically and nonsurgically treated patients.

BACKGROUND: Sprengel's deformity is a congenital anomaly of the scapula and can be associated with reduced shoulder mobility and esthetic concerns. Controversies remain regarding its natural history, radiographic findings, and optimal treatment strategy. METHODS: A total of 74 Sprengel's shoulders in 71 patients presenting to a pediatric referral hospital were retrospectively reviewed including 24 surgically treated shoulders. Median age at initial presentation was 3.8 years. Median age at the final follow-up was 9.6 years. RESULTS: Twenty shoulders were analyzed for range of motion across time. The median composite abduction range was initially 105° and at the last time-point 98°, with a median loss of 15° over 5 years (P = .007). A total of 26% of the nonsurgical shoulders reported pain at the latest follow-up, compared with 1 surgical patient (4%) (P = .028). Older age was independently associated with pain (P < .001); this effect was only seen in nonsurgical patients. Radiographically, the glenoid inclination angle (GIA) independently correlated with the abduction range (P = .001). Surgically treated shoulders underwent a modified Woodward procedure at a median 4.8 years of age. At a median follow-up of 41 months, the abduction range improved in the surgical group from 90° preoperatively to 110° postoperatively, with a median gain of 40° (P < .001). The median GIA changed from -2° to 4° with a median gain of 9° (P = .004). CONCLUSIONS: The natural history of untreated Sprengel's deformity may be one of gradual decline in the abduction range, with a proportion of patients developing pain in adolescence. The GIA correlates with the shoulder abduction range. Surgery with a modified Woodward procedure may alter the natural history of the condition by improving motion and reducing risk of pain later in life.

Intraoperative Use of Robotics With Navigation for Pedicle Screw Placement in Treatment of Pediatric High-grade Spondylolisthesis: A Preliminary Report.

BACKGROUND: Accurate pedicle screw placement is critical to surgically correct pediatric high-grade spondylolisthesis (HGS). The recent advent of robotics coupled with computer-assisted navigation (RAN) may represent a novel option to improve surgical outcomes of HGS, secondary to enhanced pedicle screw placement safety. This series presents the HGS-RAN technique adopted by our site, describing its surgical outcomes and feasibility. METHODS: Consecutive patients with a diagnosis of HGS (Meyerding grade III to V), operated on using RAN from 2019 to 2020 at a single-center were reviewed. Demographics, screw accuracy, sagittal L5-S1 parameters, complications, and perioperative outcomes were described. All patients were treated with instrumentation, decompression, posterior lumbar interbody fusion, and reduction. Robotic time included anatomic registration to end of screw placement. Screw accuracy-defined as a screw placed safely within the planned intrapedicular trajectory-was characterized by the Gertzbein-Robbins system for patients with additional 3-dimensional imaging. RESULTS: Ten HGS patients, with an average age of 13.7 years old, were included in the series. All 62 screws were placed without neurological deficit or complication. Seven patients had additional 3-dimensional imaging to assess screw accuracy (42 of 62 screws). One hundred percent of screws were placed safely with no pedicle breaches (Gertzbein-Robbins-grade A). Thirty screws (48%) were placed through separate incisions that were percutaneous/transmuscular and 32 screws (52%) were inserted through the main incision. There were statistically significant improvements in L5 slippage (P=0.002) and lumbosacral angle (P=0.002), reflecting successful HGS correction. The total median operative time was 324 minutes with the robotic usage time consuming a median of 72 minutes. Median estimated blood loss was 150 mL, and length-of-stay was a median 3 days. CONCLUSIONS: This case-series demonstrates that RAN represents a viable option for HGS repair, indicated by high screw placement accuracy, safety, and L5-S1 slippage correction. Surgeons looking to adopt an emerging technique to enhance safety and correction of pediatric HGS should consider the RAN platform. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Developmental sacral morphology: MR study from infancy to skeletal maturity.

PURPOSE: The primary aim of this study was to document the growth and spatial relationship of the sacrum in relationship to the lumbar spine and the ilium during childhood and adolescence. METHODS: MRIs of 420 asymptomatic subjects (50% female) with age range 0-19 years at the time of their MRI (mean ± SD 8.5 ± 5.5 years) were used to characterize the reference distributions of MRI anatomic measurements as a function of age and gender. Eight dimensional measurements and eight angles were measured using PACS tools. Reliability of the measurements was studied on a subset of N = 49 images (N = 24 males; mean ± SD age 6.8 ± 5.2 years). RESULTS: The dimensional measurements increase with age, often with a rapid "growth spurt" in the first few years of life, with a decreased but steady rate of growth continuing until the late teenage. An exception is the S1 canal width, which reaches near-adult size by age 5. Angle measures are less dependent on age or gender, and the associations with age are not necessarily uniformly increasing or decreasing. CONCLUSION: These data on the sacral morphology are a valuable information source for surgeons treating young patients for deformity of the spine and pelvis. Knowledge of normative data of children through growth may allow for adaptation of adult surgical techniques to this pediatric age-group of patients. These slides can be retrieved under Electronic Supplementary Material.

Criteria for surgical reduction in high-grade lumbosacral spondylolisthesis based on quality of life measures.

PURPOSE: Although surgical reduction in high-grade lumbosacral spondylolisthesis is often performed in young patients, criteria for defining adequate reduction leading to optimal outcomes have yet to be defined. The purpose of this study is to determine if surgical reduction in pelvic balance, slip grade, lumbosacral angle and L5 incidence are associated with quality of life after surgery, based on specific criteria proposed previously in the literature. METHODS: A prospective cohort of 61 patients (14.4 ± 2.7 years) with high-grade lumbosacral spondylolisthesis was followed for a minimum of 2 years after surgery. SRS-22 scores, slip grade, lumbosacral angle, pelvic balance and L5 incidence were assessed before surgery and at the latest follow-up. Multivariable regression analyses were performed using postoperative SRS domain and total scores as the dependent variables. Independent variables consisted of the preoperative SRS scores, and specific criteria of pelvic balance, slip grade, lumbosacral angle and L5 incidence. The influence of slip grade, lumbosacral angle and L5 incidence on pelvic balance was also assessed. RESULTS: Obtaining a balanced pelvis postoperatively was mainly predictive of improved satisfaction with surgery and self-image and also tended to be associated with higher scores for other domains. Improved mental health was associated with reduction to a low-grade slip. Reduction in lumbosacral angle was not predictive of quality of life. Postoperative pelvic balance was mainly associated with preoperative pelvic balance, but there was a tendency for achieving normal pelvic balance when the postoperative L5 incidence was 60° or smaller. CONCLUSIONS: When performing surgery in young patients with high-grade lumbosacral spondylolisthesis, achieving normal pelvic balance is the key because it is associated with improved quality of life. Reduction to a low-grade slip is predictive of improved mental health, but reduction in lumbosacral angle is not associated with postoperative quality of life. There was a tendency for obtaining normal postoperative balance in patients with postoperative L5 incidence 60° or smaller. These slides can be retrieved under Electronic Supplementary Material.

What Are the Indications for Spinal Fusion Surgery in Scheuermann Kyphosis?

BACKGROUND: Surgical indications for Scheuermann kyphosis are variable. We sought to evaluate the characteristics of patients undergoing operative versus nonoperative treatment of Scheuermann kyphosis to better understand current practices and the factors which contribute to the decision for surgical management. METHODS: Multicenter prospective cohort study. We evaluated consecutive patients presenting with Scheuermann kyphosis. Patients underwent either surgical or nonoperative management according to surgeon and patient discretion. Preoperative patient-reported outcome measures (Scoliosis Research Society and Spinal Appearance Questionnaire scores), demographics, and radiographic characteristics were assessed. RESULTS: Overall, 150 patients with Scheuermann kyphosis were enrolled, with 77 choosing nonoperative treatment and 73 treated operatively. Compared with the nonoperative cohort, patients treated operatively were older (16.3±2.0 vs. 15.1±2.2, P=0.0004), and had higher body mass index (26.3±7.2 vs. 22.7±6.5, P=0.003), had greater T2-T12 kyphosis (71±14 degrees vs. 61±12 degrees, P<0.001), increased pelvic incidence (46 vs. 41 degrees, P=0.03) and pelvic tilt (10 vs. 3 degrees, P=0.03). There was no detected difference in maximal sagittal Cobb angle in the operative versus nonoperative patients (73±11 vs. 70±12 degrees, P=0.11). Functionally, the operative patients had worse Scoliosis Research Society pain scores (3.7±0.9 vs. 4.1±0.7, P=0.0027) and appearance scores (2.9±0.7 vs. 3.4±0.8, P <0.0001). CONCLUSIONS: Patients undergoing surgical management of Scheuermann disease were more likely to have large body mass index and worse pain scores. Other factors beyond radiographic measurement likely contribute to the decision for surgical management of Scheuermann kyphosis. LEVEL OF EVIDENCE: Level II.

Acute Exertional Compartment Syndrome in Young Athletes: A Descriptive Case Series and Review of the Literature.

OBJECTIVES: Acute exertional compartment syndrome (AECS) is a rare presentation of acute compartment syndrome (ACS) after exertion without injury. Unfamiliarity with this entity can lead to delay in diagnosis. The purpose of this study was to increase awareness of AECS and illustrate the morbidities associated with delayed diagnosis. METHODS: With institutional review board approval, we conducted a retrospective chart review of all patients who underwent emergent fasciotomies for AECS from 1997-2013 at our institution. Male patients with sports-related closed fractures of the tibia leading to ACS were identified for comparison. Demographic variables, patient-specific factors, treatment, and outcome characteristics were analyzed. RESULTS: Seven male patients (mean age, 17 years) presented to our institution with AECS from 1997-2013, and 9 patients with fracture-related ACS were selected for comparison. All cases of AECS occurred in the leg. In the AECS group, the mean time from symptom onset to diagnosis was 97 hours. Four patients initially had a missed diagnosis. On presentation, 6 of 7 patients experienced neurologic symptoms (motor or sensory deficit), although none had perfusion deficits. The mean compartment pressure was 91 mm Hg. They all underwent isolated anterior and lateral compartment releases (except for 1 patient who required a 4-compartment release) and required a mean of 4 surgeries. The mean follow-up was 270 days. Of the 4 patients with missed diagnoses, 2 had significant neurologic and functional deficits at final follow-up. The other 5 patients had a full recovery. Fracture-related ACS patients were younger, with quicker time from symptom onset to surgery, and required more compartments to be decompressed at surgery. CONCLUSIONS: Despite the rarity of AECS, orthopedists as well as primary care, emergency medicine, and sports medicine physicians should maintain a high index of suspicion when examining a patient with leg pain out of proportion to examination after exertion. Delay in diagnosis of AECS is associated with substantial muscle necrosis and morbidity.

Predicting Postsurgical Satisfaction in Adolescents With Idiopathic Scoliosis: The Role of Presurgical Functioning and Expectations.

BACKGROUND: There is a need to better assess patient satisfaction and surgical outcomes. The purpose of the current study is to identify how preoperative expectations can impact postsurgical satisfaction among youth with adolescent idiopathic scoliosis undergoing spinal fusion surgery. METHODS: The present study includes patients with adolescent idiopathic scoliosis undergoing spinal fusion surgery enrolled in a prospective, multicentered registry examining postsurgical outcomes. The Scoliosis Research Society Questionnaire-Version 30, which assesses pain, self-image, mental health, and satisfaction with management, along with the Spinal Appearance Questionnaire, which measures surgical expectations was administered to 190 patients before surgery and 1 and 2 years postoperatively. Regression analyses with bootstrapping (with n=5000 bootstrap samples) were conducted with 99% bias-corrected confidence intervals to examine the extent to which preoperative expectations for spinal appearance mediated the relationship between presurgical mental health and pain and 2-year postsurgical satisfaction. RESULTS: Results indicate that preoperative mental health, pain, and expectations are predictive of postsurgical satisfaction. CONCLUSIONS: With the shifting health care system, physicians may want to consider patient mental health, pain, and expectations before surgery to optimize satisfaction and ultimately improve clinical care and patient outcomes. LEVEL OF EVIDENCE: Level I-prognostic study.

Staged Growing Rods With Preimplantation of Spinal Anchors for Complex Early Onset Scoliosis.

BACKGROUND: Treatment of early onset scoliosis (EOS) with growing rods (GR) can be challenging in patients with significant deformity, hyperkyphosis, or poor bone quality, due to risks of neurological deficit and hardware pull-out. The objective of this study is to report a series of EOS patients managed with a 2-stage GR technique used to minimize these complications. METHODS: Two-stage GR technique was performed in 8 patients at mean age of 5.4 (range, 3.4 to 7.9) years. At stage 1, proximal and distal anchors were implanted with local fusion. At stage 2, the distraction rods were inserted. There were at least 3 months between stages 1 and 2, and halo-gravity traction was used before stage 2 unless contraindicated. Demographic, clinical, and surgical data were retrospectively reviewed with mean 4.9 (range, 2.0 to 9.4) years of follow-up. Radiographic measurements including Cobb and kyphosis angles were evaluated before stage 1, after halo-gravity traction, after stage 2, and at last follow-up. Indications for staging, anchor healing time, and complications were collected and analyzed. RESULTS: Indications for 2-stage surgery were poor bone quality in 5 patients and neurological changes during initial attempt at GR placement in 3 patients. The mean time between stage 1 and 2 was 23 (15 to 45) weeks. Patients have undergone mean 7 (3 to 16) lengthenings. Three patients have been converted to magnetically controlled GR. The major coronal Cobb angle improved from mean 81 degrees (range, 61 to 97) preoperatively to 40 degrees (24 to 50) after stage 2 and remained at 40 degrees (27 to 53) at last follow-up. Kyphosis remained controlled from 45 degrees (10 to 76) preoperatively to 38 degrees (9 to 61) after stage 2 to 41 degrees (17 to 65) at last follow-up. Complications included superficial wound problems (4 patients), broken rods (2 patients), proximal migration (2 patients), and implant prominence (1 patient). At minimum 2-year follow-up, no patients had lingering neurological complications or instrumentation-bone failure of the GR construct. CONCLUSIONS: Two-stage GR technique can effectively be utilized in EOS patients with poor bone quality or in the event of intraoperative neurological changes. Satisfactory deformity correction can be obtained and routine serial lengthenings can take place with minimal complications. LEVEL OF EVIDENCE: Level IV- case series.

Utility of postoperative laboratory testing after posterior spinal fusion for adolescent idiopathic scoliosis.

PURPOSE: With advancements to blood management strategies, risk of perioperative transfusion following surgical treatment of adolescent idiopathic scoliosis (AIS) has diminished. We hypothesize that routine laboratory testing on postoperative-day 1 (POD1) and beyond is unnecessary. The purpose of this study is to determine necessity of POD1 labs, particularly hematocrit and hemoglobin levels, following surgical management of AIS. METHODS: We performed a retrospective cohort study of consecutive AIS patients aged 11-19 who underwent posterior spinal fusion (PSF) at a single institution. Univariable logistic regression was utilized to determine factors associated with hematocrit ≤ 22% on POD1 or a postoperative transfusion. Firth's penalized logistic regression was used for any separation in data. Youden's index was utilized to determine the optimal point on the ROC curve that maximizes both sensitivity and specificity. RESULTS: 527 patients qualified for this study. Among the eight total patients with POD1 hematocrit ≤ 22, none underwent transfusion. These patients had lower last intraoperative hematocrit levels compared to patients with POD1 hematocrit > 22% (24.1% vs 31.5%, p < 0.001), and these groups showed no difference in preoperative hematocrit levels (38.2% vs 39.8%, p = 0.11). Four patients underwent postoperative transfusion. Both preoperative hematocrit levels (34.0% vs 39.9%, p = 0.001) and last intraoperative hematocrit levels (25.1% vs 31.4%, p = 0.002) were lower compared to patients without transfusion. Intraoperative hematocrit < 26.2%, operative time of more than 35.8 min per level fused, or cell salvage > 241 cc were significant risk factors for postoperative transfusion. CONCLUSION: Transfusion after PSF for AIS is exceedingly rare. POD1 labs should be considered when last intraoperative hematocrit < 26%, operative time per level fused > 35 min, or cell salvage amount > 241 cc. Otherwise, unless symptomatic, patients do not benefit from postoperative laboratory screening.

More Than a Flesh Wound: Trisomy 21 Patients Undergoing Posterior Spinal Fusion for Scoliosis Have High Odds of Wound Complications.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Patients with trisomy 21 (T21) often have soft tissue differences that lead to greater risk of postoperative wound complications. Our aim was to use a matched cohort of adolescent idiopathic scoliosis (AIS) patients with >2 year outcomes to determine odds of specific wound complications when comparing T21 and AIS patients. METHODS: 14 T21 and 544 AIS patients were available for matching. Propensity score matching was conducted using logistic regression models and yielded a 1:5 match of 14 T21 patients and 70 AIS patients. Bivariate analyses were conducted across both patient groups. The proportion of wound complications was estimated along with a 95% confidence interval. Multivariable logistic regression analysis was utilized to determine if there was a significant association between T21 patients and wound outcomes. RESULTS: 64% of T21 patients experienced a wound complication (9/14; 95% CI = 35.63-86.02) while only 3% of the AIS patients experienced a wound complication (2/70; 95% CI = .50-10.86). Patients with T21 had 56.6 times the odds of having a wound complication compared to matched AIS patients (OR = 56.57; 95% CI = 8.12-394.35; P < .001), controlling for age at surgery, BMI percentile, and propensity score. T21 patients had 10.4 times the odds of reoperation compared to AIS patients (OR = 10.36; 95% CI = 1.62-66.02; P = .01). CONCLUSION: T21 patients have 10.4× the odds of reoperation and 56.6× the odds of overall wound complication when compared to AIS patients in a 1:5 matched cohort with appropriate controls. This is important for surgical planning, surgeon awareness, and communication with families preoperatively.

The Longitudinal Effects of Posterior Spinal Fusion with Derotation on Axial Deformity in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To characterize the change in angle of trunk rotation (ATR), axial vertebral rotation (AVR), and body surface rotation (BSR) in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with en-bloc derotation across multiple postoperative visits. SUMMARY OF BACKGROUND DATA: Previous research has documented ATR, AVR, and BSR correction for AIS patients after surgery. However, there is a lack of evidence on the sustainability of this correction over time. METHODS: This was a retrospective study from a single-center prospective surface topographic registry of patients with AIS, age 11-20 at time of surgery, who underwent PSF with en-bloc derotation. Patients with previous spine surgery were excluded. ATR was measured with a scoliometer, AVR through EOS radiographic imaging, and BSR via surface topographic scanning, Data collection occurred at: preoperative, six-week, three-month, six-month, one-year, and two-year postoperative visits. BSR and AVR were tracked at the preoperative apical vertebral level, and the level with maximum deformity, at each respective timepoint. Generalized estimating equations models were used for statistical analysis. Covariates included age, sex, and body mass index. RESULTS: 49 patients (73.4% female, mean age 14.6±2.2 years, mean preoperative coronal curve angle 57.9°±8.5, and 67% major thoracic) were evaluated. ATR correction was significantly improved at all postoperative timepoints and there was no significant loss of correction. AVR Max and AVR Apex were significantly improved at all timepoints but there was a significant loss of correction for AVR Apex between the six-week and one-year visit (P=0.032). BSR Max achieved significant improvement at the three-month visit. BSR Apex was significantly improved at the three-month and one-year visit. CONCLUSION: ATR and AVR demonstrated significant axial plane correction at two-years postoperative in patients undergoing PSF for AIS. BSR did not maintain significant improvement by the two-year visit.

Fully automated determination of robotic pedicle screw accuracy and precision utilizing computer vision algorithms.

Historically, pedicle screw accuracy measurements have relied on CT and expert visual assessment of the position of pedicle screws relative to preoperative plans. Proper pedicle screw placement is necessary to avoid complications, cost and morbidity of revision procedures. The aim of this study was to determine accuracy and precision of pedicle screw insertion via a novel computer vision algorithm using preoperative and postoperative computed tomography (CT) scans. Three cadaveric specimens were utilized. Screw placement planning on preoperative CT was performed according to standard clinical practice. Two experienced surgeons performed bilateral T2-L4 instrumentation using robotic-assisted navigation. Postoperative CT scans of the instrumented levels were obtained. Automated segmentation and computer vision techniques were employed to align each preoperative vertebra with its postoperative counterpart and then compare screw positions along all three axes. Registration accuracy was assessed by preoperatively embedding spherical markers (tantalum beads) to measure discrepancies in landmark alignment. Eighty-eight pedicle screws were placed in 3 cadavers' spines. Automated registrations between pre- and postoperative CT achieved sub-voxel accuracy. For the screw tip and tail, the mean three-dimensional errors were 1.67 mm and 1.78 mm, respectively. Mean angular deviation of screw axes from plan was 1.58°. For screw mid-pedicular accuracy, mean absolute error in the medial-lateral and superior-inferior directions were 0.75 mm and 0.60 mm, respectively. This study introduces automated algorithms for determining accuracy and precision of planned pedicle screws. Our accuracy outcomes are comparable or superior to recent robotic-assisted in vivo and cadaver studies. This computerized workflow establishes a standardized protocol for assessing pedicle screw placement accuracy and precision and provides detailed 3D translational and angular accuracy and precision for baseline comparison.

BrAIST-Calc: Prediction of Individualized Benefit From Bracing for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Prospective multicenter study data were used for model derivation and externally validated using retrospective cohort data. OBJECTIVE: Derive and validate a prognostic model of benefit from bracing for adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: The Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST) demonstrated the superiority of bracing over observation to prevent curve progression to the surgical threshold; 42% of untreated subjects had a good outcome, and 28% progressed to the surgical threshold despite bracing, likely due to poor adherence. To avoid over-treatment and to promote patient goal setting and adherence, bracing decisions (who and how much) should be based on physician and patient discussions informed by individual-level data from high-quality predictive models. MATERIALS AND METHODS: Logistic regression was used to predict curve progression to <45° at skeletal maturity (good prognosis) in 269 BrAIST subjects who were observed or braced. Predictors included age, sex, body mass index, Risser stage, Cobb angle, curve pattern, and treatment characteristics (hours of brace wear and in-brace correction). Internal and external validity were evaluated using jackknifed samples of the BrAIST data set and an independent cohort (n=299) through estimates of discrimination and calibration. RESULTS: The final model included age, sex, body mass index, Risser stage, Cobb angle, and hours of brace wear per day. The model demonstrated strong discrimination ( c -statistics 0.83-0.87) and calibration in all data sets. Classifying patients as low risk (high probability of a good prognosis) at the probability cut point of 70% resulted in a specificity of 92% and a positive predictive value of 89%. CONCLUSION: This externally validated model can be used by clinicians and families to make informed, individualized decisions about when and how much to brace to avoid progression to surgery. If widely adopted, this model could decrease overbracing of AIS, improve adherence, and, most importantly, decrease the likelihood of spinal fusion in this population.